Spider sounds like your Ute served duty in the same way a mate of mines EH Ute did.
He tells me the old guy must have driven down to the beach once a week reversed it into the ocean and taken home a load of salt water with him.
The ute I talk about had massive amounts of time rebuilding the floor while rolled onto its side ,He then lost a bit of interest and left it in the rain (on its side to fill with water) the rain in wollongong often contains fallout from BHP Steel so the Ute has very original rust holes through the quarters now.
Go figure